When considering a capper for a rifle, the Ted Cash oval capper is the best. It holds about 80 caps. You can dump your caps in the open capper, shake the capper to get most if not all of the caps upright and the springs hold the cap in place for placing on the nipple.
For cheap, effective and long lasting, I don't think you will do much better than your mustard bottles. You need to load from a flask to a measure. The best flask was part of an integrated system that dropped powder into a measure. My horn has a spring valve that releases powder to my measure. My most used measures are the ones with the swing over funnel. Once you start using a measure stay with that one funnel as each one can measure out different volumes of powder.
Your ramrod of 1/2" diameter should hold up for most use. Hardware dowel rods are not consistent in grain run out and are prone to breakage. Go to the plumbing section of your hardware store and get a 1/2" pipe fitting to use as a muzzle protector. Use a permanent marker to mark the rod to the breech so you can tell if you have loaded powder.
Get some inexpensive safety glasses and hearing protection. This can be the foam plugs or a set of ear muffs or use both.
You really don't need the most expensive gear for this to be an enjoyable hobby.